Immune response to CagA protein is associated with improved platelet count after Helicobacter pylori eradication in patients with idiopathic thrombocytopenic purpura.

BACKGROUND: Improvement in platelet counts has been reported after eradication of Helicobacter pylori in patients with idiopathic thrombocytopenic purpura (ITP). We examined the levels of serum markers of gastritis and anti-CagA (cytotoxin-associated gene A) IgG antibody in patients with ITP to investigate whether these factors are associated with the platelet response after H. pylori eradication therapy. MATERIALS AND METHODS: One hundred and sixteen consecutive patients with ITP were assessed for H. pylori infection by (13)C-urea breath test and serum H. pylori antibody test. Patients with H. pylori infection received eradication therapy. Before and after eradication therapy, we evaluated serum levels of gastrin, pepsinogen (PG)-I, and PG-II and the anti-CagA IgG antibody titer. RESULTS: H. pylori infection was found in 67 (58%) of the 116 patients with ITP. Fifty-two infected patients received eradication therapy, which was successful in 44 patients (85%). Twenty-seven patients (62%) showed an increased platelet count and were identified as responders. The duration of ITP was shorter in responders than in nonresponders (p = .017). There was no difference of the levels of gastrin and PGs between responders and nonresponders. Before eradication therapy, the serum anti-CagA antibody titer did not differ significantly between responders and nonresponders. However, reduction in the anti-CagA antibody titer after eradication therapy was significantly greater in responders than in nonresponders (p = .013). CONCLUSIONS: H. pylori eradication therapy improves the platelet count in H. pylori-positive patients with ITP of short duration. Immune response of hosts to CagA protein of H. pylori may play a role in the pathogenesis of ITP.

Involvement of proinflammatory cytokines IL-1beta and IL-6 in progression of human gastric carcinoma.

UNLABELLED: Gastric carcinoma occurs in response to chronic inflammation of gastric mucosa infected with Helicobacter pylori. It is not known how cytokines affect the growth and progression of gastric carcinoma. MATERIALS AND METHODS: We measured tissue concentrations of the proinflammatory cytokines interleukin (IL)-1beta and IL-6 in gastric carcinoma and investigated the correlation between the levels of these cytokines and clinicopathological features. Biopsy specimens of tumors or adjacent normal mucosa were obtained from 42 Japanese patients with gastric carcinoma. Tissue levels of IL-1beta and IL-6 were measured by enzyme-linked immunosorbent assay. RESULTS: IL-1beta levels were significantly higher in the neoplasm than in the corresponding normal mucosa. The IL-6 levels in the neoplasm correlated significantly with the depth of invasion and lymphatic invasion. High levels of IL-1beta and IL-6 were characteristic of non-scirrhous type gastric carcinoma. CONCLUSION: These results suggest that IL-1beta and IL-6 are involved in the growth and progression of human gastric carcinoma.

Implication of anti-parietal cell antibody levels in gastrointestinal diseases, including gastric carcinogenesis.

We investigated serum levels of anti-parietal cell antibody (APCA) in relation to various gastric diseases. Subjects were 224 Japanese patients including 58 with gastric cancer. All patients underwent gastroscopy, and APCA was investigated by enzyme-linked immunosorbent assay. Unexpectedly, there was no difference in APCA levels between patients with gastric cancer and those with gastritis. Among H. pylori-positive patients, APCA levels were closely correlated with grades of atrophy when no gastric cancer was present, but no correlation was found when gastric cancer was present. APCA-negative gastric cancer was found mainly in males and was characterized by massive infiltration of neutrophils in the background mucosa. The 24 patients with gastric cancer were APCA-negative and showed low pepsinogen levels. The odds ratio for the incidence of gastric cancer in these patients was 7.90 (95% CI 3.4-18.4). This suggests APCA-negative gastric cancer is the predominant form of gastric cancer in Japan.